Chelsea wanted a buy-back clause when they sold Romelu Lukaku. (Reuters)

Chelsea did not include a buy-back clause in Romelu Lukaku’s transfer to Everton due to Jose Mourinho’s instruction, according to reports.

The Daily Telegraph claims that during negotiations for Lukaku’s £28 million sale to Everton in the summer of 2014, Chelsea’s transfer chiefs were willing to accept a lower fee in order to have an option to re-sign the Belgian.

But Mourinho is said to have demanded that the club get as much money for the striker in order for him to have a bigger budget for his own transfer targets.

That same summer, Chelsea and Mourinho secured the £32m signing of Diego Costa from Atletico Madrid.

Mourinho wanted Chelsea to get the highest possible fee for Lukaku. (Getty Images)